Field of the Invention and Prior Art
The present invention relates to a valve device according to the description herein.
A valve device of the type here in question is previously known from the patent publication WO 00/28203 A1. This known valve device is intended to be included in an EGR system (EGR=Exhaust Gas Recirculation) of a combustion engine so as to regulate the relation between the amount of fresh air supplied to the combustion engine from the inlet air channel of the combustion engine and the amount of recirculated exhaust gases supplied to the combustion engine from the recirculation conduit of the EGR system. This mixture set by the valve device is supplied to the air intake of the engine. The valve device is in this case controlled by means of an EGR control device in dependence on inter alia the rotational speed and the load of the combustion engine. The valve device known from WO 00/28203 A1 comprises a first inlet channel intended to be connected to the recirculation conduit of the EGR system and a second inlet channel intended to be connected to the air inlet channel of the combustion engine. These inlet channels are in the valve device brought together into a common outlet channel. A first damper, here denominated EGR damper, is arranged in the first inlet channel and a second damper, here denominated air damper, is arranged in the second inlet channel. The flow of recirculated exhaust gases and fresh air, respectively, in the inlet channels is regulated by means of these dampers. In the known valve device, the dampers are spring-loaded into an open position and a regulating member in the form of a regulating pin, which is common to the dampers and rotatable by an adjustment motor, is arranged to act upon either damper for adjusting this damper between an open position and a closed position, while the other damper is kept in an open position by said spring-loading. In this known valve device, the dampers are consequently individually adjustable independently of each other by means of a common adjustment motor, which enables an adequate control of the valve device using only adjustment motor.